PROJECT SUMMARY/ABSTRACT This is an Administrative Supplement for a parent Beeson K76 career development award for Dr. Melisa Wong, a thoracic oncology clinician-investigator dually trained in medical oncology and aging research. Dr. Wong's long-term goal is to become a leader in geriatric oncology research, improving cancer care for older adults by aligning treatments with individualized patient goals. More than 72% of older adults with cancer report that they would not choose a treatment that results in functional impairment, even if it improves survival. Yet, oncologists traditionally make treatment decisions based on cancer characteristics, often without discussing how treatment might affect function or eliciting patients' goals and values. To move from cancer-centered to patient-centered decision making, oncologists must both predict which older adults are at highest risk for functional decline and communicate complex information about benefits and harms to patients in a way that aligns treatment with their goals for function, quality of life, longevity, and other priorities. This proposal aims to 1) identify risk factors for functional decline in daily activities, physical performance, and life-space mobility during chemotherapy and/or immunotherapy in older adults with metastatic lung cancer; 2A) adapt the Best Case/Worst Case (BC/WC) communication tool; and 2B) test the adapted BC/WC tool's feasibility for use during treatment discussions with older adults with lung cancer. In Aim 1's multi-clinic cohort study, patients age 65 and older with metastatic lung cancer will undergo serial geriatric assessments to measure functional status during chemotherapy and/or immunotherapy. In Aim 2A, older adults with lung cancer, caregivers, and oncologists will participate in focus groups to elicit feedback aimed at adapting the BC/WC tool to incorporate function and other patient priorities into patient-centered decision making. In Aim 2B's pre-post pilot study, oncologists will be trained to use the adapted BC/WC tool; treatment discussions with older adults with lung cancer before and after training will be analyzed. Dr. Wong's exceptional multidisciplinary mentoring team is led by Dr. Louise Walter, an internationally recognized expert on individualized decision making for cancer screening in older adults. This award will support Dr. Wong's transition to research independence through dedicated training in 1) longitudinal modeling and risk prediction for functional decline in older adults with cancer; 2) shared decision making and decision-making interventions for older adults with functional or cognitive impairment; 3) clinical trial design to test decision-making interventions for older adults with cancer; and 4) leadership skills to direct multicenter research to transform geriatric oncology care. The results from this proposal will serve as the foundation for a multicenter cohort study to develop and validate a risk prediction score for functional decline during lung cancer treatment in older adults and a cluster-randomized trial to test the effect of the adapted BC/WC tool on communication, shared decision making, and receipt of goal-concordant care.